The Seat,valve, cataloged under National Stock Number 4820-00-036-1909, is classified within Federal Supply Class 4820 (Valves, Nonpowered) of the Valves group. Government technical data includes 15 specifications, cited from the U.S. Government catalog. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4820-00-036-1909 |
| Item Name | Seat,valve |
| FSC / FSG | 4820 / 48 — Valves, Nonpowered |
| Status | ACTIVE |
| Thread Length | 0.500 INCHES NOMINAL SECOND THREADED PORTION IN |
| Thread Length | 0.812 INCHES NOMINAL FIRST THREADED PORTION IN |
| Style Designator | DOUBLE FLANGED |
| Body Inside Diameter | 1.802 INCHES NOMINAL IN |
| Nominal Thread Size | 2.625 INCHES FIRST THREADED PORTION IN |
| Nominal Thread Size | 2.812 INCHES SECOND THREADED PORTION IN |
| Thread Class | 2A SECOND THREADED PORTION A |
| Thread Class | 2A FIRST THREADED PORTION A |
| Thread Quantity Per Inch | 16 FIRST THREADED PORTION |
| Thread Quantity Per Inch | 18 SECOND THREADED PORTION |
| Material | STEEL OVERALL |
| Seat Angle in Deg | 30.000 NOMINAL |
| Thread Series Designator | UN FIRST THREADED PORTION |
| Thread Series Designator | UNS SECOND THREADED PORTION |
| Seating Surface Shape | ANGULAR |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| 84551 | 5/9 Secondary reference Ashcroft Inc Dba Heise |
| 84551 | 3/9 Design control — primary reference Dresser, Inc. Dba Dresser Equipment Group Div Industrial Valve Operations, Dresse |
NSN 4820-00-036-1909 is a Seat,valve, classified under FSC 4820, Valves, Nonpowered. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 5995-00-171-3143. Verify interchangeability with system specifications before substitution.
Key specifications for 4820-00-036-1909: Overall Height: 2.950 INCHES NOMINAL IN; Thread Length: 0.500 INCHES NOMINAL SECOND THREADED PORTION IN; Thread Length: 0.812 INCHES NOMINAL FIRST THREADED PORTION IN; Style Designator: DOUBLE FLANGED. 15 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.